Battery on my cordless circular saw won't charge - help!

Hey everyone, I'm having a problem with my cordless circular saw. The battery won't charge at all. I plug it into the charger and the light just stays green, but when I put it in the saw, it's dead. I've had the saw for about 2 years and use it occasionally for DIY projects. Any ideas? I checked the contacts and they look clean. Could it be the charger or the battery? Thanks!

Hey Dave, welcome to the club of dead batteries lol. First thing I'd do is check the charger with a multimeter to see if it's outputting voltage. If the charger is fine, then it's likely the battery. Two years isn't that long, but if you leave it discharged for long periods, it can kill the cells. Also, what brand is it? Some brands have known issues with their chargers. Also, try cleaning the contacts with isopropyl alcohol just in case. Let us know what you find.

DiyDave, I'm a contractor and I've seen this a lot. If it's a lithium-ion battery, it might have gone into a deep discharge state and the charger won't recognize it. Sometimes you can jump-start it with another battery of the same voltage, but that's risky. Also, check if the charger is actually the right one for that battery. Mixing brands can cause issues. If the battery is dead, it might be cheaper to buy a new one than to try and fix it. But first, test the charger. Good luck!

I had a similar issue with my Makita saw. Turned out the charger had a bad connection inside the plug. I wiggled the cord and the light flickered. Might be worth checking the cord and plug for any damage. Also, if you have another battery that works, try charging that one to see if the charger is the problem. If the charger works with another battery, then it's definitely the battery. If not, it's the charger. Simple swap test.

Thanks for the replies! It's a DeWalt 20V Max. I don't have another battery to test with, but I'll try the multimeter on the charger. I'll also try cleaning the contacts. If it's the battery, I'll just get a new one. I'll let you know what happens.